1. Technical Field
The present disclosure relates to radiofrequency amplifiers that use phase-shifted full bridge resonant inverters. Particularly, the present disclosure is directed to reducing the cost and complexity of the resonant inverters.
2. Background of the Related Art
Energy-based tissue treatment is well known in the art. Various types of energy (e.g., electrical, ultrasonic, microwave, cryogenic, thermal, laser, etc.) are applied to tissue to achieve a desired result. Electrosurgery involves application of high radio frequency electrical current to a surgical site to cut, ablate, coagulate or seal tissue. A source or active electrode delivers radio frequency energy from the electrosurgical generator to the tissue and a return electrode carries the current back to the generator. In monopolar electrosurgery, the source electrode is typically part of the surgical instrument held by the surgeon and applied to the tissue to be treated and the return electrode is placed remotely from the active electrode to carry the current back to the generator. In bipolar electrosurgery, one of the electrodes of the hand-held instrument functions as the active electrode and the other as the return electrode.
FIG. 1 is an example of a prior art electrosurgical generator that uses a phase-shifted full bridge resonant inverter to generate the electrosurgical energy needed to perform the electrosurgical procedure. The generator 100 includes a resonant inverter 102 and a pulse width modulation (PWM) controller 108. The resonant inverter 102 includes an H-bridge 104 an LCLC tank 106. The tank 106 includes a series inductor, a series capacitor, a parallel inductor, and a parallel capacitor. Because of the number of components in the tank 106, the cost and complexity of the resonant inverter is increased.